A Dynamic Constraint Method for Inverse Dynamics Degrees of Freedom

Abstract

The invention provides a dynamic constraint method for inverse kinematics degree of freedom. The dynamic constraint method comprises the steps of S1, setting degree-of-freedom constraint for each joint; S2, constructing a Jacobian matrix of skeleton hierarchy by each joint, when one degree of freedom of one joint is constrained, removing an element of the degree of freedom on a corresponding column of the Jacobian matrix and enabling subsequent elements to be contracted forward; S3, setting an inverse kinematics position matrix of each joint; S4, inserting the position matrices and the Jacobian matrices into an inverse kinematics numerical solver so as to obtain angle rotation results; S5, according to the degree-of-freedom constraint of each joint, selecting angle values from the angle rotation results so as to update the degree-of-freedom constraint of all joints; and S6, judging whether the degree-of-freedom constraint of each joint meets inverse kinematics computation iteration terminal conditions or not. Therefore, when the degree-of-freedom constraint is computed, the amount of computation is not increased but the computation is accelerated, and the setting of the degree-of-freedom constraint can be changed during computing.

Description

technical field [0001] The invention belongs to the technical field of degree-of-freedom constraints, and in particular relates to a dynamic constraint method for inverse dynamics degrees of freedom. Background technique [0002] When working with inverse kinematics, it is often the case that joints (such as the elbow) only need to rotate about a specific axis. According to common sense, this situation can be solved by using the angle hard constraint solution. However, the cost of hard angular constraints is very high, which will seriously slow down the calculation speed. Especially under a specific bone structure, too many hard constraints may increase the computational consumption by more than ten times. [0003] For example, most of the time inverse kinematics only needs to be calculated for one axis, robotic arm, human arm or leg inverse kinematics calculation, etc. If dynamic construction is added to the degree of freedom constraint, such as changing the bone rotatio...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a dynamic constraint method of inverse dynamics degrees of freedom to solve the problem of huge calculation consumption caused by the traditional method of adding hard constraints to deal with dynamic constraints

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